diff options
Diffstat (limited to 'src/stdio/vfwprintf.c')
-rw-r--r-- | src/stdio/vfwprintf.c | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c index f9f1ecfd..b8fff208 100644 --- a/src/stdio/vfwprintf.c +++ b/src/stdio/vfwprintf.c @@ -154,8 +154,10 @@ static void out(FILE *f, const wchar_t *s, size_t l) static int getint(wchar_t **s) { int i; - for (i=0; iswdigit(**s); (*s)++) - i = 10*i + (**s-'0'); + for (i=0; iswdigit(**s); (*s)++) { + if (i > INT_MAX/10U || **s-'0' > INT_MAX-10*i) i = -1; + else i = 10*i + (**s-'0'); + } return i; } @@ -168,8 +170,8 @@ static const char sizeprefix['y'-'a'] = { static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_arg, int *nl_type) { wchar_t *a, *z, *s=(wchar_t *)fmt; - unsigned l10n=0, litpct, fl; - int w, p; + unsigned l10n=0, fl; + int w, p, xp; union arg arg; int argpos; unsigned st, ps; @@ -181,20 +183,19 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ wchar_t wc; for (;;) { + /* This error is only specified for snprintf, but since it's + * unspecified for other forms, do the same. Stop immediately + * on overflow; otherwise %n could produce wrong results. */ + if (l > INT_MAX - cnt) goto overflow; + /* Update output count, end loop when fmt is exhausted */ - if (cnt >= 0) { - if (l > INT_MAX - cnt) { - if (!ferror(f)) errno = EOVERFLOW; - cnt = -1; - } else cnt += l; - } + cnt += l; if (!*s) break; /* Handle literal text and %% format specifiers */ for (a=s; *s && *s!='%'; s++); - litpct = wcsspn(s, L"%")/2; /* Optimize %%%% runs */ - z = s+litpct; - s += 2*litpct; + for (z=s; s[0]=='%' && s[1]=='%'; z++, s+=2); + if (z-a > INT_MAX-cnt) goto overflow; l = z-a; if (f) out(f, a, l); if (l) continue; @@ -222,9 +223,9 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ } else if (!l10n) { w = f ? va_arg(*ap, int) : 0; s++; - } else return -1; + } else goto inval; if (w<0) fl|=LEFT_ADJ, w=-w; - } else if ((w=getint(&s))<0) return -1; + } else if ((w=getint(&s))<0) goto overflow; /* Read precision */ if (*s=='.' && s[1]=='*') { @@ -235,24 +236,29 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ } else if (!l10n) { p = f ? va_arg(*ap, int) : 0; s+=2; - } else return -1; + } else goto inval; + xp = (p>=0); } else if (*s=='.') { s++; p = getint(&s); - } else p = -1; + xp = 1; + } else { + p = -1; + xp = 0; + } /* Format specifier state machine */ st=0; do { - if (OOB(*s)) return -1; + if (OOB(*s)) goto inval; ps=st; st=states[st]S(*s++); } while (st-1<STOP); - if (!st) return -1; + if (!st) goto inval; /* Check validity of argument type (nl/normal) */ if (st==NOARG) { - if (argpos>=0) return -1; + if (argpos>=0) goto inval; } else { if (argpos>=0) nl_type[argpos]=st, arg=nl_arg[argpos]; else if (f) pop_arg(&arg, st, ap); @@ -285,8 +291,9 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ continue; case 'S': a = arg.p; - z = wmemchr(a, 0, p); - if (z) p=z-a; + z = a + wcsnlen(a, p<0 ? INT_MAX : p); + if (p<0 && *z) goto overflow; + p = z-a; if (w<p) w=p; if (!(fl&LEFT_ADJ)) fprintf(f, "%*s", w-p, ""); out(f, a, p); @@ -298,9 +305,9 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ case 's': if (!arg.p) arg.p = "(null)"; bs = arg.p; - if (p<0) p = INT_MAX; - for (i=l=0; l<p && (i=mbtowc(&wc, bs, MB_LEN_MAX))>0; bs+=i, l++); + for (i=l=0; l<(p<0?INT_MAX:p) && (i=mbtowc(&wc, bs, MB_LEN_MAX))>0; bs+=i, l++); if (i<0) return -1; + if (p<0 && *bs) goto overflow; p=l; if (w<p) w=p; if (!(fl&LEFT_ADJ)) fprintf(f, "%*s", w-p, ""); @@ -315,6 +322,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ continue; } + if (xp && p<0) goto overflow; snprintf(charfmt, sizeof charfmt, "%%%s%s%s%s%s*.*%c%c", "#"+!(fl & ALT_FORM), "+"+!(fl & MARK_POS), @@ -341,6 +349,13 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_ for (; i<=NL_ARGMAX && !nl_type[i]; i++); if (i<=NL_ARGMAX) return -1; return 1; + +inval: + errno = EINVAL; + return -1; +overflow: + errno = EOVERFLOW; + return -1; } int vfwprintf(FILE *restrict f, const wchar_t *restrict fmt, va_list ap) |